PIN diode switches are used conventionally for switching high-frequency signal branches. The switches in the signal branches are conventionally realised by a combination of longitudinal switch elements and transverse switch elements. In the simplest case, such a signal branch comprises one longitudinal switch element and one transverse switch element. The transverse elements are conventionally connected to ground directly or via a block capacitor. The signal transmission within the transmission frequency range should be impaired as little as possible by the switch elements. Linear impairments are, for example, the transmission loss and error matching of such switches in the conductive pathway and the finite insulation in the disabled pathway. Non-linear impairments are level-dependent signal distortions, for example, through second-order and third-order intermodulations.
The minority-carrier lifetime of a conductive PIN diode and the current through the conductive PIN diode determine the lower high-frequency frequency limit for the use of such a switching element. If field-effect transistors are used as the switch element instead of PIN diodes, the high-frequency resistance is modulated by a connected high-frequency voltage. A variation of the blocking capacitance of a blocked PIN diode by the high-frequency voltage superposed on the blocking voltage causes non-linear distortions. In turn, if field-effect transistors are used as the switch elements, varying the blocking capacitance of blocked transverse field-effect transistors also has an influence in the form of non-linear signal distortions as a result of the high-frequency voltage superposed on the blocking voltage.
Accordingly, for example, DE 30 47 869 C1 shows a PIN-diode switch which provides the above-named disadvantages.
The invention is based upon the object of providing an electronic switch, especially for high-frequency signals, which causes only very slight non-linear distortions.